The project consists of two studies. The first study is a prospective investigation of blood pressure and heart rate in newborn infants with follow-up determinations conducted at 6, 15, and 24 months of age. The primary aims of the study are to establish the normal values of these variables in infancy, and to identify any possible racial difference in blood pressure and heart rate at this early age. The second portion of the project is an ongoing historical prospective study of the relationship between obesity, body type, social characteristics and casual blood pressure during adolescence and subsequent blood pressure levels in a predominantly white, middle-class population originally studied from 1957-1963.